The goal of the NCRCRG program is to create multidisciplinary research groups, in partnership with academia and industry, to use patient-derived reprogrammed cells to develop validated platforms for identifying novel targets and developing new therapeutics ... to reduce the burden of mental illness. Here we propose to use induced neuronal (iN) cells, derived from induced pluripotent stem (iPS) cells, to model defects in synaptic function due to three engineered or naturally-occurring mutations known to substantially increase the risk of schizophrenia (SCZ): NRXN1 exonic deletions, 22q11.2 deletions, and 16p11.2 duplications. The study includes three projects. Project 1 will analyze the functional characteristics of human iN cells. For each mutation, one component will study cells with engineered mutations vs. non-mutated cells from the same control individual, while a second component will study iN cells derived from 5 SCZ patients with the mutation of interest vs. 5 control individuals. Project 2 will analyze the same mutations in mouse models, providing both a cross-species validation of human findings, and an novel attempt to determine whether the synaptic phenotypes of these mutations are the same in iN cells, cultured primary neurons, and brain slices (medical pre-frontal cortex). Project 3 will develop and optimize stem cell methods that are required for this project (large-scale implementation of iN cell protocols; new targeted mutation strategies for large CNVs; derivation of pure inhibitory iN cells; development of a mouse-free iN cell protocol), and which will also be needed to develop future high-throughput screening assays based on the pathophysiological models developed in this study. These experiments will provide new insights into the characteristics of neurons derived by reprogramming method, into synaptic phenotypes produced by each of these mutations, and ultimately into the pathophysiology susceptibility to the risk of psychotic disorders including SCZ. We will determine whether these mutations produce distinct or at least partially overlapping synaptic phenotypes. Either observation has profound implications for future SCZ research. To accomplish this work, we have assembled an outstanding scientific team from Stanford University (Drs. Sudhof in molecular neuroscience, Wernig in stem cell biology and Levinson in genetics of schizophrenia); Rutgers University (Dr. Pang in neuroscience and stem cell biology); Cincinnati Children's Hospital Medical Center (Dr. Aronow in bioinformatics and high-content imaging); Eli Lilly and Company (Drs. Isaac and Ursu in electrophysiology, Merchant in drug development, Dage in high-content imaging and assay development, Collier in genomics and systems biology, and Eastwood in biostatistics); and Cellular Dynamics, Inc. (Dr. Swanson, representing a leading biotechnology company in stem cell biology). These projects represent a multidisciplinary effort of academic and industrial institutions to gain insight into te pathophysiology of psychotic disorders by studying three mutations that are associated with SCZ.